Although offering different focal lengths both these Olympus ‘fast’ telephoto primes are an option for portraiture or low-light photography. The Olympus M.ZUIKO DIGITAL ED 45mm f/1.8 offers a shorter focal length, which is beneficial for shooting portraits in locations where you can’t take another 3 or 4 steps back. It’s also lighter, smaller and cheaper but how does it compare optically?

Well there’s nothing between the Lens Metric Scores for Transmission, Distortion or Vignetting, although the 75mm version does score marginally better for Chromatic Aberration, 2um to 4um. This is down to the 45mm displaying some minor default at f/1.8 but in the real world there’s very little between these two lenses until you look at Sharpness. A Sharpness Lens Metric Score of 9P-Mpix for the Olympus M.ZUIKO DIGITAL ED 45mm f/1.8 isn’t bad but it can’t live up to the 75mm, which is 15% sharper than the 45mm version.

At the maximum aperture of f/1.8 the 75mm has the edge being sharper in all areas of the frame but particularly in the centre, although the 45mm is more homogeneous at this setting. Stop down to f/2.8 and sharpness of the 75mm really excels with good and homogeneous sharpness compared to the 45mm. The pattern continues at all aperture settings with the 75mm always just that little bit sharper and more consistent than its cheaper rival. It’s fair to say the 45mm is much sharper in the centre at f/2.8, compared to its own performance at f/1.8, but it suffers from heavy drop off in the corners at this setting.

Further readings for the Olympus M.ZUIKO DIGITAL ED 75mm f/1.8 review: Is this the best Micro Four Thirds lens available?

To provide photographers with a broader perspective about mobiles, lenses and cameras, here are links to articles, reviews, and analyses of photographic equipment produced by DxOMark, renown websites, magazines or blogs.

Comments

Nonsystematic\relevant comparisons?

It would be more relevant if you post comparison against other mirrorless or compact systsem cameras, rather than Nikon D3x which is more than 3x more expensive.

I'd suggest to make comparison against similar priced or sized camera, then you can mention the comparison against D3X to give the readers idea of where the 75mm + m43 system is against the whole playing field.

First replies for this comment

Re: Nonsystematic\relevant comparisons?

Hello!

Comparison between other mirror less or compact camera system are very interesting too.Sometimes we propose more "exotic" comparison like this one. Note that the first comparison we provided correspond to your request.

If you have other interesting comparison to propose, feel free to report it in this post !

DXO found the Sony sensor Olympus cameras (EM-5, E-PM2, E-PL5) to have somewhat superior dynamic range and noise characteristics than other 16 Mpix m4/3 (GH2, GX1), but the pixel pitch, and hence the hardware upper limit on resolution, is the same. The Olympus 16 Mpix cameras reportedly have weaker antialiasing filters than the the 16 Mpix Panasonics, but as I understand they still have them, so any difference in resolution tests would be smaller than the difference between the Nikon D800 and D800E (< 5%, and visible only upon pixel peeping).

Distortion is a large scale geometric defect rather than pixel level effect, and should be the same on any camera of the same mount.

Vignetting may differ on other camera mounts due to varying pixel well depth (incident light arriving at oblique angles may miss the well bottom), but 4/3 and m4/3 were designed from the start for digital sensors, with telecentric lenses and perpendicular incident light.

Transmission can be, and probably is, tested on an optical bench, with no camera at all.

Likewise, chromatic aberration can be measured in µm on an optical bench. If it were measured in pixel widths, higher resolution would make CA more visible when pixel peeping.

As an exercise, look at lenses with multiple DXOmark tests on other mounts. You'll note the same general pattern: - Camera resolution creates an upper limit on sharpness, but camera models with the same Mpix count differ trivially.- Vignetting can vary lightly on non-telecentric lenses (but not 4/3 or m4/3)- Distortion, Transmission, and Chromatic aberration are the same for a given lens regardless of mount.

So, might lens tests using an Oly 16 Mpix camera add 1 point to perceptual megapixels (P-Mpix) for the very sharpest m43 lenses (75, 60, 25). Possibly, but in my opinion only if there's a shift from rounding down to rounding up. It would have negligible impact on the relative scores of the lenses within the system or compared to others.